Wetting and detergent composition



Patented Ifi 4, l95l WE'KTKNG AND DETERGENT CUIWIPOSII'E'ION Emil ll.Vitalis, Springdale, 0011111., assignor to American tlyanarnid (Jompany,New York, N. Y a corporation oi Maine No Brag. Application November 4,1949, Serial No. 125,661

2 Clo.

This invention relates to wetting and detergent compositions containingmonoalkyl suliosuccinates together with solubillzing agents therefor.The invention includes the compositions themselves, their methods ofpreparation, and wetting and detergent processes in which thesecompositions are used.

It is known that the higher monoalkyl sulfosuccinates, when used in theform of their salts with monovalent salt-forming compounds, possess goodWetting and particularly good detergent properties. However, the saltsof monoesters of suliosuccinic acid with alcohols of 12 or more carbonatoms, which is the minimum chain length for good detergency, possessrelatively low solubility in water, which is a serious disadvantage. Itis a principal object of the present invention to provide for this classof compounds solubilizing agents which improve their water solubilityand thus increase their usefulness as wetting agents and detergents. Afurther object resides in the provision of readily soluble pastes orpowders containin the higher monoalkyl sulfosuccinates in a solubilizedand therefore Water-dispersible condition. Still further objects of theinvention will be apparent from the following detailed description ofpreferred embodiments thereof.

As is noted above the sodium, potassium, ammonium, ethanolamine andsimilar salts of the higher monoalkyl sulfosuccinates in which the alkylradical contains 12 or more carbon atoms are only slightly soluble inwater. The solubility of the disodium salts, which is given in thefollowing table, is typical of the corresponding salts of potassium andammonium as well.

Solubility,

Monoalkyl Disodium Sulfosuccinate gins [100 cc.

of Solution DodecyL 4. 5 TctradecyL 0. 05 Hcxadecyl- 0. 2 Octadecyl 0.05

carbon nature boiling at 39 C. to 96 C. at 0.3 mm. of mercury pressureand therefore containing about 14-16 carbon atoms, and about 58% ofhigher boiling materials, possibly higher alcohols. This mixture ishereinafter designated as Ammeco which is its commercial name.

Attempts have been made to solubilize these and similar compounds byaddin water-soluble alcohols, ethers of ethylene glycol and other agentswhich are known to solubilize the higher dialkyl sulfosuccinates.However, it was found that these alcohols and ethers actually reduce thewater solubility of the alkali metal and ammonium salts of highermonoallryl sulfosuccinates.

I have now discovered that water-soluble chromium salts such as chromiumsulfate, chromium chloride, chromium nitrate, and the like are excellentsolubilizing agents for the higher monoalkyl sulfosuccinate salts. Thisis a remarkable discovery, for the addition of the corresponding saltsof alkali metals such as sodium or potassium sulfate or chloride causesprecipitation of the higher monoalkyl sulfosuccinate salts instead ofsolubilizing them. I have found, however, that I can prepare stableaqueous solutions containing from about 1% to about 30% of the wettingagents, depending on the particular alcohol present in thesulfosuccinate ester, as well as water-soluble concentrated aqueouspastes containin about 30-70% of the wetting agents, and evenwater-soluble dry powders containing the higher monoalkyl sulfosuccinatesalts together with inorganic salts of the type of sodium sulfate,sodium chloride and the like by incorporating therein suitablequantities of chromium salts which ionize in aqueous solution.

The monoalkyl sulfosuccinate salts which are solubilized by chromiumsalts in accordance with the present invention have the followingformula MOaS.C.COOM

-JJOOR H2 in which M is a monovalent salt-forming group such as sodium,potassium, ammonium, ethanolamine and'the like, and R is an alkylradical, of at least 12 carbon atoms and preferably 12 to 18 carbonatoms which may be saturated or unsaturated, or a mixture of such alkylradicals. The compounds defined by the above formula are preferablyprepared by esteriiying maleic anhydride or maleic acid with dodecyl,tetradecyl, octadecyl, octadecenyl or other alcohols containing 12 ormore carbon atoms at about loll- C. to form the monoester, followed bysuli'onating this ester to form the sulfosuccinate. Preferably thesulfonation is carried out by heating the ester with an aqueous solutionof sodium sulfite, or sodium metabisulfite, or of the correspondingpotassium or ammonium compounds. By this method the alkali metal andammonium salts of the monoalkyl sulfosuccinic acid esters are obtaineddirectly.

The corresponding salts of ethanolamine and other bases are preferablyproduced by first acidifying an alcoholic solution of the alkali metalor ammonium sulfosuccinates, whereby the free sulfosuccinic acidmonoester is obtained, filtering off the inorganic salt of the acid usedand reacting the sulfosuccinic acid ester with the desired base. Saltsof other metals such as calcium, barium, zinc, tin, lead and the likeare prepared by adding stoichiometric quantities of their oxides orhydroxides to the alcoholic sulfosuccinic acid monoester followed bystirringuntil the salt formation is complete. Salts of organic basessuch as methylamine, ethylamine, ethanolamine and the like may also beprepared by the same method.

For many purposes it is desirable to prepare the higher monoalkylsulfosuccinates in the form of dry, water-dispersible powders.Heretofore this has not been possible, for upon evaporation of theirsolutions in water or organic solvents the compounds form a white pastymass similar in texture to ordinary soap. The compounds are precipitatedfrom their aqueous solutions by the addition of ammonium, sodium, orpotassium salts, and therefore the addition of sodium or potassiumsulfate or chloride to form a dry, freeflowing powder could not beresorted to.

Another important feature of the present invention is the discovery thatthe solubilizing action of water-soluble chromium salts persists even inthe presence of sodium sulfate, sodium chloride and other salts whichwould ordinarily precipitate the higher monoalkyl sulfosuccinate saltsfrom their water solutions. This discovery has enabled me to preparedry, free-flowing powders containing the higher monoalkyl sulfosuccinatesalts in admixture with water-soluble alkali metal compounds, or inadmixture with watersoluble ammonium compounds, which powders arereadily soluble in cold water. No material change in the ratio ofchromium salt to monoallryl sulfosuccinate salt need be made when otherwater-soluble salts are added; i. e., the solubilizing action of thechromium salts is the same in the presence of sodium sulfate, sodiumchloride and the like as it is in the absence of these salts. However,it has been found that while the upper limit of diluent which may beemployed depends entirely on the desired concentration of wetting agentin the dry mixture, the lower limit of diluent is not substantially lessthan 40% of the mixture. For example, when a dry mix is preparedcontaining more than about 60% of the monoalkyl sulfosuccinate, thematerial is not easily soluble in cold water; for this reason drymixtures containing in excess of about 60% 'of monoalkyl sulfosuccinateare not included within the purview of this invention.

Inpraeticing the invention, the amounts of chromium salts to be employedvary according to the original water solubility of the various monoalkylsulfosuccinate salts. It will be readily apparent that dodecyl disodiumsulfosuccinate, having a water solubility of 4.5 grams per 100 cc., willrequire the addition of less chromium salt than will disodium hexadecylsulfosuccinate, for

ill

Per Cent Per Cent Solubility, Solubility, Molar Ratio, gms./l00 cc.gmsJlOO cc. Chromium at 30 0., No at 30 0., to Succinate ChromiumCrz(S0|): Salt Salt Addu. Added Dodccyl 4. 5 8 2/511 Dodecyl 4. 5 203/5zl Tctradecyl. 0.05 5 3/511 Hexadecyl. 0. 2 10 3 :l Mixture 0. 2 9315:! Octadccyl. 0.05 2 1:1

The sulfosuccinate mixture above referred to is that prepared fromAmmecol.

As is common in the case of the solubility of salts, higher solutiontemperatures result in an increase of the solubility of the varioussalts. In the case of the present invention, such variations in solutiontemperatures permit the use of smaller amounts-of the solubilizingchromium salts. For this reason, the lower limits of such salt additionsmay in some cases and for some purposes be within the range of from 0.25mol to 0.5 mol per mol of sulfosuccinate salt employed. On the otherhand, while there is no absolute upper limit of chromium salt additionsince the solubilizing agent does not interfere with the wetting anddetergent properties of the monoalkyl sulfosuccinates, for mostcommercial applications not more than about 7 to 10 mols of chromiumsalt should be employed for each mol of sulfosuccinate. Moreover, I havefound that the most preferable quantity of chromium salt to be employedis from 0.25 mol to 1 mol for each mol of the sulfosuccinate dependingon its water solubility.

Conversely, in preparing aqueous pastes and dry powders containingwater-soluble inorganic salts of monovalent metals such as sodium andpotassium, larger amount of chromium salts may of course be used,although amounts substantially larger than those given in the abovetable are not usually necessary.

It is evident, therefore, that the invention in its broader aspects isnot limited to the use of large quantities of the chromium salts butthat relatively small proportions of these salts may be used if desired.

The invention will be illustrated in greater detail by the followingspecific examples. It should be understood, however, that although theseexamples may describe in detail certain specific features of theinvention, they are given primaril for purposes of illustration and theinvention in its broader aspects is not limited thereto. All parts ivenare by weight.

Example 1 A paste was prepared by mixing together 95 parts of a 30%aqueous gel of a disodium monoalkyl sulfosuccinate prepared fromAmmecol, and 5 parts of CI2(SO4)3. The paste was used to prepare anaqueous solution containing 9% of the sulfosuccinate salt. The materialwas completely soluble and the solution remained clear at temperaturesof from 6-10 0., whereas the same sul- Example 2 A dry, free-flowingpowder was obtained by drying to 100 parts an aqueous mixture consistingof 116 parts of a 30% aqueous gel of the disodium monoalkylsulfosuccinate mixture employed in Example 1, 6 parts of CI2(SO4)3, and69 parts of N82SO4. The dried powder formed clear solutions with waterwhen used in concentrations up to 9%.

Example 3 To 100 cc. of a 2% aqueous dispersion of dipotassium cetylsulfosuccinate was added 7.2 cc. of a 10% CIC13.6H2O solution (1:0.67molar ratio). Within a short period of time the initially cloudydispersion became clear, indicating that a true solution of thesulfosuccinate had been obtained.

Example 4 To 100 cc. of a 2% aqueous dispersion of diammonium cetylsulfosuccinate was added 11.0 cc. of a 10% C1(NO3)3.7H2O solution(1:0.67 molar ratio). Within a short period of time the initially cloudydispersion became clear, indicating that a true solution of thesulfosuccinate had been obtained.

Example 5 To 100 cc. of a 5% aqueous dispersion of disodium oleylsulfosuccinate was added 7.5 cc. of a CrClzfiHzO solution (1:0.67 molarratio). Within a short period of time the initially cloudy dispersionbecame clear, indicating that a true solution of the sulfosuccinate hadbeen obtained.

It has also been found that chromic bromide suitably solubilize thehigher monoalkyl suli'osuccinates similarly to chromic chloride.

Example 6 A W ting and detergent composition 1 t1.

prising essentially a surface active material which is a monoalkylsuliosuccinate having the formula H MOri-COOM COOR in which M i a memberof the group consisting of alkali metal and ammonium radicals and bothM' are the same, and R is an alkyl radical of from 12 to 18 carbonatoms, and a water-soluble inorganic chromium salt which is capableofincreasing the water solubility of the monoalkyl suliosuccinate, saidchromium salt being present in an amount the minimum range of which isfrom 0.25 mol to 1 mol and the maximum amount is 10 mols for each mol ofthe sulfosuccinate.

2. A wetting and detergent composition comprising essentially a. surfaceactive material which is a mixture of monoalkyl sulfosuccinates havingthe formula H MOaS.$.COOM

.COOR

in which M is a member of the group consisting of alkali metal andammonium radicals and both Ms are the same, and R. is an alkyl radicalof from 12 to 18 carbon atoms, and a watersoluble inorganic chromiumsalt which is capable of increasing the water olubility of the mixtureof monoalkyl sulfosuccinates, said chromium salt being present in anamount the minimum range of which is from 0.25 mol to 1 mol and themaximum amount is 10 mols for each mol of the sulfosuccinates.

EMIL A. VITALIS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,181,087 Caryl et a1 Nov. 21,1939 2,316,234 Flett Apr. 13, 1943 OTHER REFERENCES Aerosol WettingAgents, publication of Amer. Cyanamid and Chem. Corp., N. Y., (1941).DD.

1. A WETTING AND DETERGENT COMPOSITION COMPRISING ESSENTIALLY A SURFACEACTIVE MATERIAL WHICH IS A MONOALKYL SULFOSUCCINATE HAVING THE FORMULA